The invention concerns a device for loading packages into a cargo hold, particularly of an aircraft.
The cargo holds for luggage, for example of smaller-sized aircraft, are as a general rule positioned in the lower part of the fuselage and extend in the longitudinal direction of the fuselage in a relatively elongate yet small-height structural configuration. In order to fill these cargo holds while making full use of the capacity of the cargo hold, it is necessary to introduce the packages such as, e.g., passengers"" luggage into the cargo hold in such a way that the far end area of the cargo hold located opposite a charging opening will also be filled. Such loading of packages has hitherto, however, mostly been performed manually, was cumbersome and very time-consuming.
In order to eliminate this kind of problem, document EP 0 305 391 B1 discloses a loading system comprising a revolving conveyor in the manner of a single carpet extending across the width of the cargo hold. This carpet-type conveyor entirely covers up the cargo hold floor in front of a movable loading bulkhead and has a shape which is adapted to the contour of the aircraft""s fuselage. The conveyor enables complete filling of the cargo hold by starting in the area of the charging opening inasmuch as the respective packages can be charged onto the foremost area of the conveyor located in front of the loading bulkhead and will, by and by, be moved in such a way that the charged packages are transported away from the charging opening into the cargo hold. Unloading is performed by reversing this process.
This known loading device performs satisfactorily. As high traction forces may be required at the conveyor particularly during the unloading process, with these forces having to be supported at deflection means arranged in the area of the charging opening and having the form of a guide profile to there deflect the conveyor, mounting the guide profile such as to resist longitudinal forces constitutes a particular problem. If the guide profile transmits such forces to the hull of the aircraft, there is the risk of damage to the hull of the aircraft in the event of peak longitudinal forces (such as, say, due to the suitcases jamming upon unloading).
In order to prevent the forces generated by supporting the frontside deflection of the conveyor from being introduced into the hull of the aircraft, the teaching of EP 0 305 391 B1 relies on a continuous sliding panel between the guide profile in the area of the charging opening and the drive means located at the opposite end of the cargo hold for supporting the guide profile against longitudinal forces. This requires a pressure-resistant conformation of the sliding panel. The assembly according to EP 0 305 391 B1 is suited for this type of support inasmuch as the trough-shaped sliding panel for the single conveyor described there is secured against buckling by its very shape. Mounting of the overall assembly against the acceleration and deceleration forces occurring in flight is achieved by the mounting for the conveyor drive means as well as at the ends of the guide profile. This frame-side fixation of the overall assembly is, however, relieved of the high longitudinal forces which the drive means exert on the conveyor because these forces are intercepted as completely as possible within the overall assembly.
The pressure-resistant conformation of the sliding panel does, however, result in a heavy and/or expensive construction of the sliding panel and in a quite considerable plate thickness.
Document DE 42 38 095 A1 discloses a loading system comprising a conveyor which covers up the cargo hold floor in front of a movable loading bulkhead. Further, the loading system has a shape which is adapted to the contour of the aircraft""s fuselage. A deflection means arranged at a charging opening of the cargo hold for deflecting the conveyor is according to this known art supported by a rod which interacts with the area of the drive unit in order to absorb longitudinal forces occurring during the loading process or the unloading process. In one embodiment, the rod is arranged spaced from the floor of the cargo hold and formed so as to be deformable in one lateral direction thereof. Thus, the bar will be elastically deformed into abutment with the floor of the cargo hold as soon as cargo is loaded onto the conveyor. In a second embodiment, the rod is connected with the floor by a brace so that forces immediately can be transmitted to the floor of the cargo hold.
The invention is therefore based on the object of furnishing a generic loading device which, in comparison, presents a lightweight and slim construction at low production costs, however without forgoing a maximum degree of reliable absorption within the loading device of the peak longitudinal forces occurring during the loading process and in particular during the unloading process.
This object is attained by the characterising features of claim 1.
Subdividing the conveyor into a plurality of transport paths in accordance with the invention allows for a substantially simplified construction of the loading device as, owing to this configuration, supporting members mounted on the floor side may be arranged between transport paths possibly having a planar design. Here it was found that even relatively simple and lightweight supporting members are sufficient for effectively and reliably supporting the deflection means against the opposite end of the loading device.
Due to the fact that the supporting members are mounted on the floor side, buckling of the loading device even in the event of extreme tensile forces can reliably be avoided. The loading device therefore possesses high reliability in operation and a long service life.
Moreover the strains occurring during operation of the loading device are intercepted substantially entirely within the loading device xe2x80x9csystemxe2x80x9d instead of being introduced into the hull of the aircraft. The loading device thus represents a closed system inside the cargo hold and does not create any substantial stresses to its surroundings. Damage to the hull of the aircraft is therefore effectively prevented.
Subdividing the conveyor into a plurality of transport paths creates the additional advantage of reducing the requirements in manufacture and in guiding the transport paths. Furthermore these transport paths may be removed singly, for instance for inspection purposes, in order to grant access to particular areas of the cargo hold floor.
Herein subdivision of the conveyor does not amount to a substantial restriction of convenience of use in comparison with the prior art because the area not covered up by the transport paths and thus not movable is relatively small. Comfortable and complete filling of the cargo hold is thus possible.
It is moreover of advantage that subdividing the conveyor results in a reduction of transverse forces in the conveyor, whereby warping of the transport paths can be reduced essentially and the service life is consequently increased.
It is one more advantage that, without incurring major expenses, the supporting members also allow for increased stability of the overall assembly, whereby even greater loads than in conventional systems can be accommodated through simple means.
Another advantage of the invention resides in the fact that the supporting members mounted on the floor side allow for absorbing dynamic loads resulting, for example, from in-flight turbulences. The reliability and service life of the loading system is thereby further increased.
Inasmuch as the supporting members have the form of longitudinal beams, reliable absorption of the occurring longitudinal forces is possible without necessity for substantive expenses in terms of construction. Manufacture of the loading system according to the invention may therefore be carried out in a simple manner without major expense in terms of costs and time. In addition, the total weight of the assembly may be kept low.
It is moreover advantageous if the support members are held by positive fit on the floor side in the cargo hold so that vertical displacement is substantially precluded whereas longitudinal movement is provided for at the mounting locations. Hereby the introduction of longitudinal forces via the mounting locations at the floor of the cargo space is avoided altogether. In this way, the application of inadmissibly great loads on the cargo hold floor, which might prove detrimental to the fuselage of an aircraft, is prevented from the very beginning. The overall stability of the cargo hold is consequently not degraded.
At the same time, there results the additional advantage that a displacement of the conveyor carrying the packages may be substantially precluded even in a vertical direction in particular during a flight. Such displacement might, for instance, be caused in turbulences owing to the dynamic conditions and would bring about detrimental bending strains. The restricted vertical mobility of the supporting members, on the other hand, advantageously results in a restriction of the vibrations which might occur. The connection at the mounting locations may furthermore be formed to be resilient for additional attenuation of vibrations.
Due to the fact that one sliding panel each is at least partly arranged between the runs of the transport paths and laterally supported in the longitudinal beams and/or lateral supports in the cargo hold, there advantageously results a further effect of stabilisation of the loading system. These sliding panels permit stiffening of the supporting members. As they preferably present a surface having good sliding properties, they moreover enable in a manner known per se to reduce the friction of the transport paths loaded with packages. At the same time they separate the runs of the transport paths moving in countercurrent to reduce the introduction of opposing forces into the paths.
If the transport paths are moreover laterally guided in the longitudinal beams and at the outer edge areas of the conveyor in guide means provided at the side wall of the cargo hold, reliable support of the transport paths is obtained. Lateral shifting of the carpet-type transport paths, together with the warping possibly taking place as a result, may thus be prevented or at least reduced. The reliability and service life of the loading system is hereby further increased.
It is moreover advantageous to form projecting sections which cover the longitudinal beams at least on some of the transport paths. In this way it is possible that immovable sections which might inhibit transport of the packages in the cargo hold are not exposed anywhere in the entire floor area.